An actuator used in jet engine and aircraft control systems should reliably and precisely sense the position of the object that it controls. Often, a position sensor (transducer) is connected to the actuator to accomplish these functions. When an actuator is used in a jet engine or aircraft control system, the sensor sends a signal to a location outside the actuator for display in the cockpit or for processing by electronic controls. Some sensors used in these applications use electromagnetic devices that transmit their output signals as voltages. More recently, optical position sensors using optic fibers for signal transmission have found favor because of their lower weight and insensitivity to disturbance from strong electromagnetic interference.
One type of electromagnetic sensor provides two voltage signals related to the motion of the object being sensed. A first voltage signal (V.sub.1) increases linearly with the motion of the object in a first direction, while a second voltage signal (V.sub.2) decreases linearly with motion of the object in the same direction. If the sum of the two signals, V.sub.1 +V.sub.2, is constant, then the position P of the object relative to a fixed point is determined by: ##EQU1## where K is a scaling constant.